1. Technical Field
The present invention relates to a pump system and a method of controlling the same for cleaning strainer, and more particularly, to a pump system configured and operated to clean the strainers, which are essential components in normal pumps, easily and conveniently, and a method of controlling the same for cleaning strainer.
2. Discussion of Related Art
Pumps are normally used for pumping fluids such as water by using the centrifugal force of an impeller rotated by a motor through a suction part to a discharge pipe. They are widely used in a variety of purposes and places including crop irrigation, wastewater disposal, building construction, etc. in order to pump underground water, wastewater, floodwater, industrial usage water, etc.
Typically, strainers are installed in the pump system in order to filter and inhibit solid particulates and/or debris inside the water under the pump or inside pump pipes.
FIG. 1 is a schematic view of a typical pump system with strainers installed in the lower side of the pump. Such typical pump system includes a main pump side (depicted in A line of the drawing) and a stand-by pump side (depicted in B line of the drawing), and while the A line pump operates, the B line pump is stopped.
FIG. 1 shows a parallel-type pump system with the A line pump and the B line pump aligned in parallel, which are respectively composed of pump components of main and stand-by butterfly valves 11 and 21, main and stand-by check valves 12 and 22, main and stand-by circulation pumps 13 and 23, main and stand-by strainers 14 and 24, and main and stand-by butterfly valves 15 and 25.
The strainer is composed of a net or metal plate having a plurality of filtering holes. As such, the strainers 14 and 24 are positioned the inlet of the circulation pumps 13 and 23 with connected thereto.
The circulation pumps 13 and 23 operate so that water passes through the strainers 14 and 24 and is suctioned into the pump inlet and drained out through the pump outlet. During this operation, the contaminants inside the water such as solid particulates and/or debris are filtered by the filtering holes (not shown) of the strainers 14 and 24. The strainers 14 and 24 function as filter to inhibit particulates and/or debris from entering the inside of the pump system.
In the pump operation as such, the filtering holes of the strainers 14 and 24 are blocked by greater sized contaminants not passing through the holes when fluid such as underground water, waste water, etc. is suctioned up from the fluid source to the pump pipes.
When the water is further restricted to flow through the strainers and the flow size of the strainers 14 and 24 permitting the water flow is further reduced, the suction ability of the circulation pumps 12 and 22 is rapidly decreased and the pumping performance is rapidly decreased because motor energy unnecessarily otherwise is lost so as to cause overload in its motor.
Further, the increase of contaminants entrapment in the strainers brings a problem of decreasing the pumping capacity as failing to pump enough fluid as desired to optimal value and reach the target amount and difficulties in controlling the fluid flow.
While such pumps operate for long time and the pumping suction is further reduced because the particulates/debris are increased in the strainers and water flow is blocked by such strainers, the strainers need to clean frequently or to be removed for exchange, but the pumping operation of the pump system needs to be stopped so as to cause loss of time and efforts.
Further, the cleaning and/or the exchange of the strainers may cause inconveniences and difficulties of damaging the gasket when loosen each bolt of the strainers and removing the insulating means when take its cover apart and making insulation material being heated.